1) See attached figure
The relationship between charge and current is:
where
i is the current
Q is the charge
t is the time
Therefore, the current is the rate of change of the charge passing through a given point over time.
This means that for a graph of charge over time, the current is just equal to the slope of the graph.
For the graph in this problem:
- Between t = 0 and t = 2 s, the slope is

therefore the current is
i = 25 A
- Between t = 2 s and t = 6 s, the slope is

therefore the current is
i = -25 A
- Between t = 6 s and t = 8 s, the slope is

therefore the current is
i = 25 A
The figure attached show these values plotted on a graph.
2)
The previous equation can be rewritten as
This equation is valid if the current is constant: if the current is not constant, then the total charge is simply equal to the area under a current vs time graph.
Here we have the current vs time graph, so we gave to find the area under it.
The area of the first triangle is:

While the area of the second square is

So, the total area (and the total charge) is

Answer:
Semiconductor. sorry i'm late
Explanation:
Answer:
1,050 Joules
Explanation:
<u>Step 1:</u> work done in moving the box 30 meters
work done = force X distance
= 25N X 30 = 750 Joules
<u>Step 2: </u>calculate total internal energy
Total internal energy = work done + kinetic energy
= 750 Joules + 300 Joules
= 1,050 Joules = 1.05 KJ
Yes yes yes yes yes yes yes yes
Given:
Momentum of the dog (p) = 120.5 kg m/s
Speed of the dog (v) = 5 m/s
To Find:
Mass of the dog (m)
Concept/Theory:

- It is defined as the quantity of motion contained in a body.
- It is measured as the product of mass of the body and it's speed.
- It is represented by p.
- It's SI unit is kg m/s
- Mathematical Representation/Equation of Momentum:

Answer:
By using equation of momentum, we get:

Mass of the dog (m) = 24.1 kg